Free Tools – Cartes Du Ciel and Virtual Moon Atlas

One of the premier tools available free to the amateur observer is the planetarium program that goes by the French name “Cartes Du Ciel.” True to its name, this program is a Sky Chart system that incorporates many of the features of full feature programs costing hundreds of dollars.

I have a number of sky charts that I find to be very useful in book form. When I am searching for a double star or a Messier Object, I really like these bound versions of sky charts. However, for some purposes, a software program is very handy. That is especially true when trying to track down comets, planets, and asteroids. The planetarium program can be set for today, or for next week when I will be out at a dark sky site. It can give different magnification levels, and I can create both right side up views for my finder scope as well as upside down and backwards views for my Dobsonian scope. Fact is, the program will also create right side up and reversed left right views for SCT scopes too!

For planning a Messier Marathon, the program is a great way to create a set of star hopping charts or to add to a published set, as I described in my Messier marathon piece last winter.

My preferred set up is to use a black on white format. It prints very well. With a red filter on a laptop computer it is also easy to read in the dark.

One of the ways I use the program is to print out a full sky chart to use instead of a planisphere for a certain time/place/and date. It is a little easier to show constellations to folks with this round version of the sky than a squished planisphere version – it also is more accurate than most planispheres for my south Texas observing location.

One of the things I like most about the Cartes du Ciel program is the ability to scale to any magnification and to add or subract star detail. This allows me to create simple charts and detailed charts on the fly. If I am interested in seeing very dim stars near where an asteroid is to be found in an eyepiece view, I can do that. If I am interested in seeing the overall picture of a full constellation, I can do that too.

Switching gears, I might as well mention the lunar equivalent of this planetarium program. The “Virtual Moon Atlas” is a great tool for locating almost all the small objects that one might be interested in on the lunar surface. It is a searchable atlas, and will identify any crater or feature that I click on the picture of the moon. There are several levels of complexity of the moon atlas. I have always used the biggest version. I really don’t know how limited the other versions might be.
Again the cool thing about this atlas is that it follows the libration of the moon, the phases of the moon, and the visible portion of the moon from any observing location. The view can also be adjusted up/down and left/right for any sort of scope.

Both programs can be downloaded from the Internet. Google search for them, download, install, and enjoy.